Pressure fields in an industrial UF module: effect of backwash

Abstract

In the last decade, membrane manufacturers have improved their ultrafiltration module to raise the production of drinking water in order to meet an increasing demand. The usual process used is an inside-out filtration in dead-end mode. In this configuration, the energy consumption is limited by outside-in backwashes. Raising the permeability of the membranes lead to an increase in module compactness and strongly modify the driving force in the module. This study presents a computational fluid dynamics (CFD) model to predict the pressure and velocity field in the hollow fiber network (HFN) taking into account several parameters as the geometry of the module, the inlet pressure, gravity, and temperature. For the industrial tested module configuration, results shown that hollow fibers work in a homogeneous way in filtration mode but a great heterogeneity appear during the backwash. All the results have been validated compared with experimental values.

Keywords:

• Ultrafiltration
• Hollow fiber module
• Pressure and velocity fields
• Backwash

Acknowledgments

The CFD computations were performed using STARCCM+ code from CD-ADAPCO.

Notes

Presented at the Conference on Membranes in Drinking and Industrial Water Production. Leeuwarden, The Netherlands, 10–12 September 2012. Organized by the European Desalination Society and Wetsus Centre for Sustainable Water Technology